[Toybox] [PATCH] Add makefile rule to build kconfig; fixes clean-tree parallel builds

[Rob Landley]

On 2/7/26 17:00, Avery Terrel wrote:
> Commit 35e26cec34 introduced a bug where `make -j32` will fail because generated/unstripped/kconfig is missing.

Toybox's Makefile is mostly just a wrapper around scripts/make.sh and 
scripts/install.sh and so on. Parallelism is autodetected via nproc in 
scripts/make.sh ("CPUS=1 make" disables it, or you can use taskset) so 
parallelism at the Makefile level doesn't get tested a lot because the 
"-j" value just says how parallel make is about launching single 
instances of shell scripts.

That said, it used to work...

[days pass...]

Ok, I've simplified a lot of the make plumbing and moved even more of it 
into scripts, plus converted more config targets from old kconfig to the 
new kconfig plumbing, and stopped telling make about more than one 
output file from scripts/genconfig.sh (which rebuilds all of them when 
run so none should be significantly newer/older).

It no longer gets confused by "make -j32" for me, and no longer does 
"silentoldconfig" using the old kconfig plumbing (but uses the new 
plumbing instead) which I _think_ was android's main gripe about 
snapshotting the generated/ directory?

(Note that "make defconfig toybox -j32" complains that toybox is 
unconfigured because it doesn't know the various config targets are 
creating .config, dunno how to add a rule for that...)

Anyway, in theory, android could now just do something like:

KCONFIG_ALLCONFIG=scripts/android_miniconfig scripts/genconfig.sh -n &&
scripts/make.sh

And... it might work? (Don't have the test environment.)

For macos and friends, I created a new scripts/prereq/use.sh that runs 
the corresponding hermetic build.sh as necessary, sticks it at the start 
of the $PATH, and runs the rest of the build under that. So now you can 
just go:

$ scripts/prereq/use.sh scripts/macos_miniconfig

And toybox should build without homebrew.

While that's a hermetic build creating its own prerequisites, I dunno if 
AOSP would want to use it because the first step is a single-threaded cc 
*.c style build of the toybox-prereq binary. (Because if all else fails, 
scripts/prereq/build.sh should work on 20th century gilligan's island 
style coconut technology. Well, assuming a sufficiently competent C11 
compiler that handles a ? : b and such, anyway. But the command line 
parts should be reasonably hermetic, lemme know if they aren't.)

Rob